Re: [PATCH crypto 1/2] lib/crypto: blake2s-generic: reduce code size on small systems

[Geert Uytterhoeven]

Hi Jason,

On Tue, Jan 11, 2022 at 2:49 PM Jason A. Donenfeld <Jason@xxxxxxxxx> wrote:
> Re-wind the loops entirely on kernels optimized for code size. This is
> really not good at all performance-wise. But on m68k, it shaves off 4k
> of code size, which is apparently important.

On arm32:

add/remove: 1/0 grow/shrink: 0/1 up/down: 160/-4212 (-4052)
Function                                     old     new   delta
blake2s_sigma                                  -     160    +160
blake2s_compress_generic                    4872     660   -4212
Total: Before=9846148, After=9842096, chg -0.04%

On arm64:

add/remove: 1/2 grow/shrink: 0/1 up/down: 160/-4584 (-4424)
Function                                     old     new   delta
blake2s_sigma                                  -     160    +160
e843419@0710_00007634_e8a0                     8       -      -8
e843419@0441_0000423a_178c                     8       -      -8
blake2s_compress_generic                    5088     520   -4568
Total: Before=32800278, After=32795854, chg -0.01%

> Signed-off-by: Jason A. Donenfeld <Jason@xxxxxxxxx>

For the size reduction:
Tested-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds